On Feb 2, 2016, at 5:04 PM, Eric Blake wrote:
> On 02/02/2016 02:23 PM, Programmingkid wrote:
>
>>> And why isn't bsd_path usable for that purpose?
>>
>> After trying it out, I found out why bsd_path isn't usable for that purpose.
>> It is because the user might try to use a flash drive as the the cdrom. Say
>> a flash drive is set to /dev/disk2s9. If the user issues the monitor command
>> "change ide1-cd0 /dev/disk2s9", this will make "if (strcmp(filename,
>> "/dev/cdrom") == 0)" false and bsd_path would never be set. bsd_path
>> contents would be garbage.
>>
>> This would lead to this code not printing the unmounting directions:
>>
>> if (strncmp(filename, "/dev/", 5) == 0) {
>> print_unmounting_directions(filename);
>> return -1;
>> }
>>
>> It looks keeping filename as an character array is best.
>
> No, keep filename as a const char * pointer. It's easy to avoid use of
> uninitialized memory. Try this:
>
> const char *filename;
> char bsd_path[MAXPATHLEN] = "";
> ...
> if (strncmp("/dev/cdrom"...) {
> bsd_path = ...
> }
> ...
> if (strncmp("/dev/"...) {
> print_unmounting_directions(*bsd_path ? bsd_path : filename);
At first I thought this code looked unusual, but it does work. Is this ok?
#if defined(__APPLE__) && defined(__MACH__)
/* if a physical device experienced an error while being opened */
if (strncmp((*bsd_path ? bsd_path : filename), "/dev/", 5) == 0) {
print_unmounting_directions(*bsd_path ? bsd_path : filename);
return -1;
}
#endif /* defined(__APPLE__) && defined(__MACH__) */
